Sheet-feeding apparatus

ABSTRACT

A PHOTOCOPYING MACHINE HAS A STORAGE COMPARTMENT WHICH IS COVERED BY A LID AND CONTAINS A STACK OF COPY PAPER SHEETS LATERALLY CONFINED BETWEEN GUIDE RAILS IN A FEEDING POSITION. ROTATABLY DRIVEN FEED ROLLERS ADVANCE THE TOPMOST SHEET FORWARDLY FROM THE FEEDING POSITION TOWARD AN EXIT THROAT, AND THE TOPMOST SHEET IS SEPARATED FROM THE REMAINDER OF THE STACK BY CORNER SEPARATORS ENGAGING THE FORWARD CORNERS OF THE STACK. FROM THE STACK, THE SHEET MOVES THROUGH THE EXIT THROAT WHICH GUIDES THE INCOMING SHEET INTO THE NIP OF A PAIR OF ROTATING ROLLERS WHICH REMOVE THE SHEET FROM THE COMPARTMENT FOR FURTHER PROCESSING. TO INSERT A FRESH STACK OF SHEETS INTO THE COMPARTMENT, THE FEED ROLLERS AND THE CORNER SEPARATORS ARE SUPPORTED FOR GENERALLY VERTICAL MOVEMENT AND MECHANICALLY CONNECTED TO THE LID SO AS TO MOVE UPWARDLY FROM THE FEEDING POSITION UPON MOVEMENT OF THE LID TO UNCOVER THE COMPARTMENT. THE FORWARD END OF THE STACK IS ALIGNED WITH THE CORNER SEPARATORS BY A PIVOTALLY SUPPORTED STOP MEMBER WHICH IS MECHANICALLY CONNECTED TO THE LID AND PIVOTALLY MOVED INTO AN UPRIGHT POSITION FOR ENGAGEMENT BY THE STACK UPON THE UNCOVERING MOVEMENT OF THE LID. AFTER THE STACK IS PROPERLY INSERTED, THE LID IS MOVED TO COVER THE COMPARTMENT AND MOVES THE STOP MEMBER FROM THE UPRIGHT POSITION AND MOVES THE SHEET ADVANCING MEANS AND THE CORNER SEPARATORS ONTO THE TOPMOST SHEET OF THE STACK.

United States Patent [72] Inventors ElmerL.Csaba Highland Park;

Edward W. Engel, Northbrook, 11]. [2|] ApplNo 801,014 [22] Filed Feb.20, 1969 [45] Patented June 28, 1971 [73] Assignee SCM Corporation NewYork, N.Y.

[54] SHEET-FEEDING APPARATUS 12 Claims, 6 Drawing Figs.

11in "nun" Primary Examiner]oseph Wegbreit Attorneys-Gerald S. Schur andKeith D. Moore ABSTRACT: A photocopying machine has a storagecompartment which is covered by a lid and contains a stack of copy papersheets laterally confined between guide rails in a feeding position.Rotatably driven feed rollers advance the topmost sheet forwardly fromthe feeding position toward an exit throat, and the topmost sheet isseparated from the remainder of the stack by comer separators engagingthe forward comers of the stack. From the stack, the sheet moves throughthe exit throat which guides the incoming sheet into the nip of a pairof rotating rollers which remove the sheet from the compartment forfurther processing. To insert a fresh stack of sheets into thecompartment, the feed rollers and the comer separators are supported forgenerally vertical movement and mechanically connected to the lid so asto move upwardly from the feeding position upon movement of the lid touncover the compartment. The forward end of the stack is aligned withthe corner separators by a pivotally supported stop member which ismechanically connected to the lid and pivotally moved into an uprightposition for engagement by the stack upon the uncovering movement of thelid. After the stack is properly inserted, the lid is moved to cover thecompartment and moves the stop member from the upright position andmoves the sheet advancing means and the corner separators onto thetopmost sheet of the stack.

PATENTEDJUH28I87I 3586 106 SHEU 1 BF 4 M EDWARD w- ENGEL ELMER L. CSABAwa is SHEET-FEEDING APPARATUS This invention relates to an apparatus forseparately advancing a stack of sheets from a feeding position, and moreparticularly to a photocopying machine having a paper storagecompartment containing a sheet-feeding apparatus for separating andadvancing-the topmost sheet from the stack and moving it into the nip ofa pair of rotating rollers which remove the sheet from the compartmentfor further processing. The compartment is normally covered with a lid,and to place a stack of paper in the feeding position, the lid must bemoved to uncover the compartment and the apparatus must be moved fromthe feeding position. In addition, the stack must be aligned with thefeeding position so that the stack of sheets may be properly engaged bythe sheet-feeding apparatus. Finally, the sheet-feeding apparatus ismoved into engagement with the properly positioned stack and thecompartment is covered by the lid in preparation for subsequentoperation.

Accordingly, an object of the present invention is to provide aphotocopying machine having a sheet-feeding apparatus which may beeasily moved relative to the feeding position to enable a fresh stack ofpaper to be placed into the storage compartment and aligned with thefeeding position for subsequent processing by the photocopying machine.

Another object of the present invention is to provide a forward stop foraligning the forward end of the stack of the copy paper being insertedinto the compartment with the feeding position, wherein the forward stopis separate from the apparatus for separating the advancing topmostsheet from the remainder of the stack.

An additional object of the present invention is to provide a forwardstop which is movable into an upright position upon lifting of the lidcovering the paper storage compartment, but which is moved out ofengagement with a stack properly inserted into the compartment uponlowering of the lid.

A further object of the present invention is to provide a sheet-feedingapparatus having sheet-separating means and forward stop means which areseparate from each other and independently movable'so as to provide astorage compartment having greater capacity than a sheet-feedingmechanism in which the forward stop and the corner separators are formedintegrally.

Still other objects, features and advantages of the present inventionwill be apparent to those skilled in the art from a reading of thefollowing detailed description of a single embodiment of the inventiontaken in conjunction with the accompanying drawings, wherein:

FIG. 1 is fragmentary perspective view of a preferred embodiment of aphotocopying machine having a sheet-feeding apparatus according to thepresent invention, and showing the topmost sheet being advancedforwardly from the stack;

FIG. 2 is a cross-sectional view of the sheet-feeding apparatus takengenerally along the lines 2-2 in FIG. 1, illustrating the condition ofthe apparatus when all of the sheets of paper have been fed from thestorage compartment;

FIG. 3 is a view of the sheet-feeding apparatus shown in FIG. 2,illustrating the condition of the sheet-feeding apparatus when the lidis lifted for inserting a stack of paper into the compartment;

FIG. 4 is a cross-sectional view of the sheet-feeding apparatus takengenerally along the lines 44 in FIG. 1, showing a stack of copy papersheets properly inserted into the compartment with the lid in a raisedposition;

FIG. 5 is a cross-sectional view taken generally along the lines 5-5 inFIG. 4, illustrating the mechanical connections between hingedlyconnected lid and the feed rollers, the corner separators, and theforward stop;

FIG. 6 is a view of the sheet-feeding apparatus shown in FIG. 4,illustrating the condition of the sheet-feeding apparatus with the stackof sheets properly inserted and the lid covering the compartment.

Referring generally to the figures in the drawings and particularly toFIG. 1, there is shown a photocopying machine,

generally indicated 11, for copying original documents onto sheets ofcopy paper. Except as indicated below, the machine 11 is generally ofthe type described in U.S. Pat. No 3,330,179, entitled AutomaticPhotocopying Machine. The machine 11 includes a housing 13 having anupper storage compartment, generally indicated 15, with an opening,generally indicated 16, which is covered by a lid 17 and contains astack 19 of copy paper sheets in a feeding position. The

' sheets are advanced separately from the feeding position and throughan exit throat, generally indicated at 21, which guides the incomingsheets into the nip of a pair of cooperating rollers 23, 25. The rollers23, 25 are mounted on drive shafts, 27,

29 respectively, which are rotatably driven by suitable means, notshown, to remove the sheets from the storage compartment 15 for furtherprocessing in the machine 11. The means for rotatably driving shafts 27,29 have been omitted from the description, since they form no part ofthe present invention and are adequately described in theabove-mentioned U.S. Patent.

Inside the housing 13, the stack 19 is supported on a substantiallyhorizontal floor 31 of a tray 33 which is supported between twosidewalls 35, 37 to form the storage compartment 15. The sheets formingthe stack 19 are laterally confined in the feeding position between twoguide rails 39, 41 which are symmetrically opposite and carried by thetray 33. The guide rails 39, 41 serve to align the stack 19 with the nipof the rollers 23, 25, and are laterally movable to accommodate sheetsof different widths therebetween. The guide rails 39, 41 may be held inposition on the floor 31 of the tray 33 by any suitable means. As moreparticularly shown in FIGS. 1 and 2, the guide rails 39, 41 havedepending lugs 43 extending downwardly through a lateral slot 45 in thefloor 31 with heads 47 on the lower end thereof which engage the floor31 of the tray 33 in a suitable friction fit.

As shown, the topmost sheet 49 is being advanced forwardly from thestack 19 by sheet-advancing means, generally indicated 51, including apair of rubber-covered feed rollers 53, 55 which are fixedly mounted ona rotating shaft 57. The shaft 57 is rotatably driven by the drive shaft27 through a belt drive, generally indicated by 59, which is located atone end of the shafts 27, 55. The belt drive 59, as shown, includes aconventional timing pulley belt 61 extending around timing pulleys 63,65 which are fixedly mounted on the ends of the shafts 27, 57respectively, although other suitable belt drives may be used, forexample a friction belt drive. The belt 61 is maintained taut and theshaft 57 is supported for generally vertical movement in parallel spacedrelation to the shaft 27 by arms 69, 71 which are pivotally connected tothe drive shaft 27. The weight exerted on the stack 19 by the rollers53, 55, the shaft 57, and the pulley 65 is generally sufficient toprovide the necessary frictional engagement between the rubber-coveredrollers 53, 55 and the topmost sheet 49, so as to enable the rotatablydriven rollers 53, 55 to forwardly advance the sheet 49. Although only asingle belt drive 59 is illustrated in the preferred embodiment, it isto be understood that suitable belt drives may be located at both endsof the shafts 27, 55. In addition, the belt drive 59 could be located atthe opposite ends of the shafts 27, 55 instead of as shown in FIG. 1.Also, additional weights may be suitably placed on the shaft 57 toincrease the frictional engagement between the rubber-covered rollers53, 55 and the topmost sheet 49.

As the topmost sheet 49 is advanced, the adjacent sheets of the stack 19move forward due to the frictional contact between the sheets of copypaper. The forward movement of the sheets may be retarded by suitablefriction pads 73 placed on the inner sides of the guide rails 39, 41 inengagement with the sides of the stack 19. To prevent more than onesheet at a time from being fed into the nip of the rollers 23, 25,separator means, generally indicated at 75, are provided to separate thetopmost sheet 49 from the remainder of the stack 19. In the preferredembodiment, the separator means 75 are in the form of corner separators77, 79 which are symmetrically opposite and engage the forward cornersof the stack 19. The corner separator 77 includes a lip 81 resting on acorner of the topmost sheet 49 and a down-tumed forward portion 83,which is more clearly shown in FIG. 5, engaging the forward end of thestack 19. Since the other comer separator 79, engaging the other forwardcomer of the stack 19, is similar to comer separator 77, identicalreference numerals have been placed on similar portions thereof.

Upon advancement of the topmost sheet 49 by the rotatably driven feedrollers 53, 55, the lips 81 of the corner separators 77, 79 hold theforward corners of the sheet 49 and cause them to buckle and bend asshown in P16. 1. As is known, the forward corners continue to bend untilthe resiliency of the advancing sheet 49 causes the forward comersthereof to move over the lips 81 of the corner separators 77, 79,thereby separating the topmost sheet 49 from the remainder of the stack19. Further advancement of the topmost sheet 49 moves it into the exitthroat 21 which, in the preferred embodiment, is formed by an upwardlyinclined forward portion 85 of the floor 31 in conjunction with agenerally horizontal plate 87 which is suitably attached to the tray 33.The converging exit throat 21 guides the incoming sheet 49 into the nipof the rotatably driven rollers 23, 25 which remove the sheet 47 fromthe compartment for further processing in the photocopying machine 11.

As the sheets forming the stack 19 are fed from the compartment 15, thestack 19 diminishes and the sheet-advancing means 51 move downwardly,with the shaft 57 being received in notches 89, 91 formed in the guiderails 39, 41 respectively. The comer separators 77, 79 are supported forgenerally vertical movement so as to maintain engagement with thetopmost sheet of the diminishing stack 19. Although the cornerseparators might be suitably supported for only vertical movement, inthe preferred embodiment the corner separators are supported forgenerally vertical movement in an arcuate path by pivotally mounted arms93, 95. The arms 93, 95 extend along the outer sides of the guide rails39, 41 and are pivotally mounted on the rearward portions thereof,although the arms 93, 95 might be mounted on suitable independentpivots.

Due to the pivotal mounting of the corner separators 77, 79, theymovedownwardly through an arcuate path, and accordingly the forward end ofthe stack of sheets must be aligned in relation to the arcuate path soas to prevent the corner separators 77, 79 from binding with the lowersheets of the stack 19. Also, it is necessary for the down-turnedforward portion 83 of the corner separators 77, 79 to move past thesurface of the floor 31 of the tray 33 to enable the lower sheets to befed from the compartment 15. As shown, the forward portions 83 of thecorner separators 77, 79 extend downwardly through openings 97, 99respectively, provided in the floor 31 until the lips 81 rest on thefloor 31 of the tray 33 after the last sheet of copy paper has been fedfrom the compartment 15.

When it is desirable to insert another stack 19 of copy paper sheetsinto the photocopying machine 11, it is first necessary to move the lid17 covering the opening 16 of the compartment 15. As shown, to enablethe compartment 15 to be easily uncovered, the lid 17 is hingedlyconnected to the machine by a pair of arcuate-shaped brackets 101, 103,each having one end thereof connected to the lid 17 and the other endpivotally mounted on the sidewalls 35, 37. in addition, the sheetadvancing means 51, along with the corner separators 77, 79 must beraised upwardly from the feeding position to enable the stack 19 to beplaced on the floor 31 of the tray 33. Furthermore, as previouslymentioned, the forward end of the stack 19 must be aligned relative tothe arcuate path followed by the downwardly moving corner separators 77,79 so as to prevent the forward edges of the lower sheets of the stack19 from interfering with the downward movement of the corner separators77, 79.

To enable a stack of sheets to be easily placed in the feeding positionin the compartment 15, the corner separators 77, 79 are provided withmeans for enabling them to be moved with the raising and lowering of thelid 17. As shown, the arcuateshaped brackets 101, 103 are provided withinwardly protruding pins 105, 107 respectively, for engaging thepivotally mounted arms 69, 71 respectively. Upon lifting the lid 17upwardly to the position shown in FIG. 3, the pins 105, 107 engage thearms 69, 71 respectivelyand move the sheet-advancing means 51 upwardlyfrom the feeding position. The upwardly moving arms 69, 71 and the shaft57, along with the brackets 101, 103 and the pins 105, 107 serve aslifting means for the comer separators 77, 79. The arms 93, supportingthe corner separators 77 79 are provided with carrying means in the fonnof fingers 109, 111 respectively, for engagement by the shaft 57, so asto move the corner separators 77, 79 upwardly and downwardly as the lid17 is raised and lowered.

To align the forward end of the stack with the arcuate path followed bythe downwardly moving separators 77, 79, stop means must be provided forengagement by the forward end of the stack being placed on the floor 31of the tray 33. In addition to properly aligning the forward end of thestack with the feeding position, the stop means must be movable from thepath of the forwardly advancing sheet as the sheets are fed from thecompartment 15. In the past, stop means have been provided by extendingthe down-turned forward portions 83 of the corner separators 77, 79 to alength at least equal to the thickness of the stack of sheets beingplaced on the tray 33. To properly align the forward end of the stack soas to prevent binding, the extended portions 83 had an arcuateconfiguration which conformed to the arcuate path followed by thedownwardly moving separators 77, 79. Other arrangements used in the pasthave included a forward stop which is mechanically connected to thecorner separators 77, 79 but not integral with them. Such a forward stopis often in the form of a vertical post which is located between thecorner separators 77, 79 and descends through an opening formed in thefloor 31 of the tray 33 as the corner separators 77, 79 move downwardly.

Such prior arrangements are not always desirable because theynecessitate a clearance beneath the floor 31 of the tray 33substantially equal to the vertical length of the stop means. Thisclearance is necessary for receiving the stop means, whether in the formof an independent vertical post or extensions of the corner separators77, 79, beneath the floor 31 of the tray 33. Such prior art arrangementsnecessarily limit the space in the machine 11 available for the paperstorage compartment 15, because space must be provided both above andbelow the floor 31 of the tray 33 for the forward stop means.Furthermore, the space beneath the tray 33 may be severely restricted bythe location of other parts in the photocopying machine, and thus mayprevent the stop means from descending substantially the full verticallength beneath the floor 31 of the tray 33.

According to the present invention, the photocopying machine 11 isprovided with a forward stop means, generally indicated at 113, which ismovable to and from an upright position for engagement by a stack ofsheets in accordance with the raising and lowering of the lid 17. Asmore particularly shown in FIGS. 2--6, the forward stop means 113 is inthe form of a stop member 115 which is located between the cornerseparators 77, 79 and extends through an opening 117 formed in theinclined portion 85 of the fioor 31. The stop member 115 is supportedfor pivotal movement to and from the upright position by having thelower end thereof fixedly connected by suitable means to a shaft 119which is rotatably supported beneath the floor 31 of the tray 33 bybrackets 121, 123 connected to the bottom side of the floor 31. Theshaft 119 extends laterally to one side of the tray 33 and is rotated bya member 125 which, in the preferred embodiment, is in the form of anarm fixedly attached thereto. The arm 125 serves to move the stop member115 in accordance with the raising and lowering of the lid 17 and has aslot 127 which receives the protruding pin for movement therein.

Although the stop member is pivotally supported in the preferredembodiment by the shaft 117 which is mounted beneath the floor 31 of thetray 33, it could also be pivotally supported by a shaft mounted abovethe floor 31 of the tray 33. In addition, the stop member 115 could bepivotally moved by another form of mechanical linkage instead of the pin105 engaging the arm 125 which, in turn, is connected to the shaft 119.For example, a gear linkage could be used wherein a gear mounted on theshaft 119 is driven by another gear or portion thereof connected to thepivotal mounting of the arcuate-shaped bracket 101.

As the lid 17 is lifted to the position shown in FIGS. 3-5, the pin 105follows an arcuate path and moves along the slot 127 formed in the arm125 to pivotally move the stop member 115 to an upright position foraligning a stack of sheets in the feeding position in the compartment15. As more particularly shown in FIG. 3, when the forward stop member115 is in an upright or generally perpendicular position, it is spacedslightly rearward of the forward down-turned portion 83 of the comerseparators 77, 79 to compensate for the arcuate path of the cornerseparators 77, 79. Accordingly, when a stack of sheets is inserted intothe compartment in engagement with the forward stop member 115, as shownin FIG. 4, the lower sheets of the stack are rearward of the down-turnedportions 85 of the comer separators 77, 79 to enable them to movedownwardly in an arcuate path without binding on the lower sheets of thestack. In addition, since the forward stop member 115 is separate fromthe corner separators 77, 79, the downturned forward portions 85 needonly extend a length sufficient to engage the topmost sheets of thestack, and therefore need not extend a substantial vertical distancebeneath the floor of the tray.

After the stack of sheets has been placed on the floor 31 of the tray 33in alignment with the feeding position, the lid 17 is lowered as shownin FIG.- 6 so as to cover the opening of the storage compartment andprepare the machine 11 for operation. As the lid is lowered, the pins105, 107 supporting the sheet advancing means 51 move downwardly throughan arcuate path and lower the rubber-covered feed rollers 53,55 onto thetopmost sheet of the stack. The corner separators 77, 79, which aresupported by the fingers 109, 111 engaging the shaft 57, likewise movedownwardly until the lips 81 thereof rest on the corners of the topmostsheet. Further lowering of the lid 17 moves the pin 105 along thearcuate path and in the slot 127 of the arm 125, thereby pivotallymoving the forward stop member 115 onto the upwardly inclined portion 85of the floor 31, thus enabling the sheets to be forwardly advanced fromthe feeding position during subsequent operation of the machine.

When the photocopying machine is again operated for producing copies oforiginal documents, the rubber'covered feed rollers 53, 55 are rotatablydriven to advance the topmost sheet 49. Due to the frictional contactbetween the sheets forming the stack, the advancement of the topmostsheet tends to move the stack forwardly. Although the friction pads 73retard the forward movement of the stack, the adjacent topmost sheetsmove forwardly into engagement with the down-turned portions 83 of thecorner separators 77, 79. As previously described, further advancementof the topmost sheet by the rotatably driven rollers buckles and bendsthe forward corners thereof until the resiliency of the sheet moves theforward corners over the lips 81, thereby separating the topmost sheetfrom the remainder of the stack. The rotatably driven rollers 53, 55continue to advance the topmost sheet and move it into the convergingexit throat 21. The exit throat 2] guides the incoming sheet into thenip of the rotatably driven rollers 23, 25 which in turn remove thesheet from the storage compartment 15 for further processing.

While only a single embodiment has been illustrated and described, itwill be apparent to those skilled in the art that various modificationsand improvements may be made without departing from the scope and spiritof the invention. Accordingly, it is to be understood that the inventionis not to be limited by the illustrative embodiment, but only by thescope of the depending claims.

We claim:

1. In a photocopying machine, the combination comprising a storagecompartment for supporting a stack of generally in a feeding positionfrom which they may be separately advanced from said compartment, stopmeans for aligning the stack of sheets in said feeding position in saidcompartment, said stop means being supported for movement in saidfeeding position, said storage compartment having an opening forinserting a stack of sheets into said compartment, a lid for coveringsaid opening of said storage compartment and supported for movementrelative thereto, said lid being movable in one direction for uncoveringsaid opening of said storage compartment to enable a stack of sheets tobe inserted therein, moving means operable upon the uncovering movementof said lid for moving said stop means to a generally upright positionat said feeding position for engagement by the forward end of the stack,said lid being movable in another direction for covering said opening ofsaid storage compartment, and said moving means being operable upon thecovering movement of said lid for moving said stop means from saidgenerally upright position in said compartment.

2. In a photocopying machine according to claim 1, said lid beingsupported for pivotal movement relative to said opening of said storagecompartment, said moving means including a moving member connected tosaid pivotally .moving stop means for pivotally moving said stop meansin response to movement of said lid, said moving means further includinga bracket carried by said lid and movable therewith for engaging saidmember, said bracket being operable upon raising said lid for movingsaid stop means to said generally upright position for engagement withthe forward end ofa stack of sheets being inserted into said compartmentand being operable upon lowering said lid for moving said stop meansfrom said generally upright position in said compartment.

3. In a photocopying machine according to claim 2, said moving memberbeing an arm connected to said pivotally supported stop means, saidbracket having a pin extending in a direction generally transverse tosaid arm, and said arm having a slot formed therein which receives saidpin for movement in said slot, whereby raising said lid moves said pinalong said slot in said arm to pivotally move said stop means to saidgenerally upright position and lowering said lid moves said pin inanother direction along said slot for moving said stop means from saidgenerally upright position in said compartment.

4. Apparatus for advancing sheets from a stack comprising asubstantially horizontal support for supporting a stack of sheets in afeeding position from which the sheets may be separately advanced,sheet-advancing means for advancing the sheets from said feedingposition, stop means for aligning the stack of sheets with said feedingposition on said horizontal support, said stop means being supported formovement to an upright position at said feeding position for engagementby a stack of sheets being placed on said horizontal support, saidsheet-advancing means being movable from said feeding position to enablea stack of sheets to be placed on said horizontal support, moving meansoperable upon the movement of said sheet-advancing means from saidfeeding position for moving said stop means to said generally uprightposition for engagement by the forward end of the stack of sheets beingplaced on said horizontal support, said sheet-advancing means beingmovable to said feeding position in engagement with the topmost sheet ofthe stack, and said moving means being operable upon the movement ofsaid sheet advancing means to said feeding position for moving said stopmeans from engagement with the forward end of the stack.

5. Apparatus for advancing sheets from a stack according to claim 4,said stop means being supported for pivotal movement, said moving meansbeing operable upon the movement of said sheet-advancing means from saidfeeding position for pivotally moving said stop means to said generallyupright position for engagement by the forward end of the stack ofsheets being placed on said substantially horizontal support, and saidmoving means being operable upon the movement of said sheet advancingmeans to said feeding position for pivotally moving said stop means fromsaid generally upright position.

6. Apparatus for advancing sheets from a stack according to claim 5,wherein said stop means includes a rotatably supported shaft, said stopmeans further including a stop member connected to said rotatablysupported shaft for pivotal movement about the axis of said shaft, andsaid moving means in cluding a moving member for rotating said shaft,said moving member being connected to said shaft and laterally spacedfrom said stop member.

7. Apparatus for advancing sheets from a stack according to claim 6,said shaft being rotatably supported beneath said horizontal support,and said moving member being an arm connected to said rotatablysupported shaft, said arm being pivotally movable about the axis of saidshaft for pivotally moving said stop member to and from said uprightposition.

8. In a duplicating machine, the combination comprising a paper feedtray having a substantially horizontal floor for supporting a stack ofsheets in a feeding position from which the sheets may be separatelyadvanced, sheet-separating means for separating an advancing sheet fromthe remainder of the stack at the feeding position, said sheetseparatingmeans being carried by said tray and supported for movement rela tive tosaid feeding position for engagement with the stack of sheets at saidfeeding position, stop means for aligning the stack of sheets with saidsheet-separating means at said feeding position on said tray, said stopmeans being supported by said paper feed tray and movable to an uprightposition for engagement by the forward end of the stack of sheets beingplaced on said tray in said feeding position, said stop means beingseparate from said sheet-separating means and movable independentlythereof, means for moving said stop means relative to said feedingposition, said means being operable for moving said stop means to saidupright position at said feeding position to enable a stack of sheets tobe placed on said tray and aligned with said sheet separating means, andsaid means being operable for moving said stop means from said uprightposition at said feeding position with said sheet-separating means inengagement with the stack of sheets.

9. In a duplicating machine according to claim 8, said stop meansincluding a stop member supported for pivotal movement to an uprightposition at said feeding position for engagement by the stack of sheetsbeing placed on said feed tray.

10. In a duplicating machine according to claim 9, said stop meansincluding a shaft rotatably supported by said tray beneath said feedingposition, said stop member being connected to said shaft for pivotalmovement about the axis thereof, and said means includes a moving memberlaterally spaced from said stop member and connected to said rotatablysupported shaft for pivotally moving said stop member to and from saidupright position.

11. A duplicating machine according to claim 10, said floor of said trayhaving a forward portion adjacent to said feeding position, said forwardportion of said tray having an opening formed therein adjacent to saidfeeding position, said stop member extending through said opening insaid forward portion of said tray and being pivotally supported by saidtray beneath said feeding position.

12. In a duplicating machine according to claim 11, said forward portionof said tray being inclined from said floor to serve as a guide forsheets advanced from said feeding position and said stop member beingpivotally movable from said upright position into engagement with saidinclined forward portion.

